Home Depot expoxy kit is terrible and will only last for about a year. Also if you do your own porcelain and ceramic fixtures then you should spray it through an HVLP system like graco 3800 or better yet Wagner has really good turbines..
But like all trades it takes a lot of pratice to get the hang of it. So if you are doing this for the first time then most likely you are going to have runs, orange peel and a rough tub..
Also restoring clawfoot tubs take extra care I wouldn't do a clawfoot for no less then $500 but that's the average price for having a clawfoot tub done correct.
When you do your tub and have to have it redone correctly by a technician then expect to pay heavy service charge for stripping of the previous application on a clawfoot tub that needs to be stripped and redone it should run about $700.
Could always forget about the vintage bathroom and just install a steel tub for that price..