good lord 200something is way to much for a spike costume. would that be including like shoes and wig and actual jacket (cause although alot of people will wear a blazer for spike is not really in the current style its kinda spacey-fied). then MAYBE. but if your looking just to do something passable then i would indeed go goodwilling. i would normally be able to commission that for less than the price you found, unfortunately im all booked for kumori already.
if there arent places in your hometown to look for clothes try on ebay or something.
but i cant keep myself from mentioning, and i mean no disrespect, that those two characters are going to be in high supply at any con. so if you care about showing up in the same clothes as other people id think about searching your nerd-dom for some other ideas. i dont know i feel weird about showing up in the same costume as a bunch of other people. like wearing the same dress as someone else to prom or some other fancy party. but thats just one of my own obsesive things. if youre cool with it go for it.