To minimize cost and still have ownership in the effort, do most of the prep work then outsource the paint job. Whoever does the paint will still do some minimal prep but the majority of it can be done by you.
In disassembly, use 3x5 cards and ziplock sandwich bags to identify groups of parts, front brake, bottom bracket, headset, all in seperate bags with cards to identify if you need to. When a project lasts weeks, this is good way to keep the parts together. I place them all in a plastic bin like the ones sold in Costco, or a shoe box with the rest loose. You can also use tie straps to keep the sequence of parts in order like a head set. Assembly screws with washers in the right sequence to minimize loose parts.