One of the largest mistakes people do is purchase a van and underestimate the time and cost associated to building out a van. There is a very good reason builds costs from 40-100k easily starting with an empty cargo van. Watching videos, reading build blogs, Instagram feeds are entertainment; and it can be super easy to assume building a van is easy and fast. Even with "kits" that claim that they can be installed in a week, often in reality take 2-3 times that to install by a DIYer. Many details in building out a van "budget" can be greatly over looked by someone who has not built a van before, especially from a blank canvas. Ever do a home remodel or kitchen remodel? Yep it's exactly like that, but a van is not an investment for profit, its an investment for experiences it will give you.
Time and Materials
Simply put building a campervan is like building a small home. Electrical, plumbing, framing, insulation, are typically all part of a build, and homes are not cheap if built correctly. Unlike a home however, a van is a moving, vibrating, home that is put under undue stress due to dramatic temper changes, constantly flexing structure, and extreme vibration in an ultra compact space. This requires specialist skills and understanding choosing the right materials, parts, tools, and installing them in a highly customized manner correctly so that it will hold up to the abuse of a moving vehicle.
Just like a home DIY project compared to a pro. What can take a professional to do in a few hours can easily take an entire day, several trips to the hardware store to complete, that might even move the project into a two day mission. Doing upgrades in the proper order as well can greatly affect costs in the build and avoid huge mistakes. It's no mystery that automotive repair rates range from $100-$300 an hour. Plumbers and electricians charge similar rates as well for specialist work. With even the most simple projects in a van can be an entire day's work especially if done by a DIYer. Research, correct parts selection, and having all the right tools takes a considerable amount of time for something even as simple as mounting some swivel seats or installing a window in a van. We often have project we do for clients that take us a few hours that can easily take a DIYer 5-6 hours. This is not including time ordering or picking up a part(s), receiving and stocking those parts, and providing warranty service on the work and parts that are often not considered as part of the cost of a project. Typical "simple" van build we do is typically between 100-150 build hours, and that is at our speed with the right tools, knowledge, and all the parts and tidbits as they say available.
There can be depending on the part you are looking for lead time of 6-12 weeks to get many parts for a build.
For Example a window install of an AMA window in a cargo van
Shipping $200-350 from manufacture for single window
Urethane glue and primer $100
Primer for metal edge $10
Tools: Metal Saw, Compressor, grinder, urethane glue gun
Time: DIY 3-4 hours, professional 2-3 hours
Clean up and disposal of old window, packaging, receiving and ordering the correct parts
Potential for damaged glass from shipping (happens more often than you would think)
This as well can be something that is often miscalculated as explained in the above example of something you watched on Instagram that took 30 seconds to do. Electrical work in particular is really underestimated in time and materials. Correct wiring, fuses, brackets, and connectors are often over looked in electrical work in particular as part of the costs of installing that "simple" auxiliary battery in your van. It can really ad up, not to mention the technical part of of just picking the right parts as these systems are built to a specific spec and not all materials are the same, not all batteries are the same as well. There are huge differences in material and parts choices.
Conclusion. If you want to save money on your project the easiest way to do this is purchase "kits" from a manufacture that can give you properly support and has a long history of documented install record by DIYer's and do it yourself. Its important however that you understand exactly how much support you will need. Don't make the mistake of watching a you tube video and going to your local home supply store and trying a remodel in your kitchen. Yep most likely it can turn out to be a disaster if you don't have the correct resources and skill set to do a project in a specific time frame. Even the super experienced influencers on the internet spend tons of time do do even a "simple" project. I saw a recent super popular influencer do a custom floor that took them 3 days between two of them...and this was by far not their first van.
You can easily cut your budget by 1/3 to 1/2 depending on the type of build. Plan on it taking a much more time than you think, enjoy the project, figure you will make some mistakes, some of them might be a bit costly but its part of the learning process. Some of our builds take only a few weeks to finish for our clients, what you don't see is the 15+ work hours a day we put in 7 days a week to get it done in two weeks. Builders can get a van done in a week...with 3-4 guys working on the van every day with everything already prepped to be put in.
Pick the right parts with manufactures that will support you (Or choose a good builder)
Do your research (don't believe everything you read on the internet)
Build in the correct sequence (Roof rack for example- do that last)
Expect Challenges along the way if DIY (Have fun, yes you will make some mistakes likley)
Figure your costs will exceed your budget