I think tire's should be kept in mind for buying new rims. I bought new falken502's for my teg and i got the quote for 15'' 16'' and 17'' tire size's same model. According to my dealer the stock 195/55/15 (55 series, stock oem) never goes on sale, thus it's a little more expensive.
As for the 17'' rims, tires such as mine, 205/40/17 do go on sale and is cheaper than the 15'' tires. BUT the 16'' tire series are the most expensive(these don't go on sale either). depending on what brand tire you purchase. Since your not going all out precise tuning status as of right now, you should think slight performance vs slight presentable (im not saying all 17''s look nice x_x i just think it looks well fitted on my car).
So a break down of previous posts + mine - 17'' i bigger, goes on sale (thus cheaper) | 16'' better performance from what everyone^^, bigger than stock, most expensive. and finally 15'' if your thinking of keeping your blades or fat fives or mesh w.e - if you don't want your revs to miss match, the 55 series do Not go on sale, thus maybe close to the price of 16's.
( you don't have to go with falkens but here's another reference -
http://www.vulcantire.com/ze502_t.htm )
go for what you want and whats in your price range, im just trying to help
have a good day-
oh and - i have 17x7 offset 42, lowered on skunk 2. if you don't lower your car you wont rub otherwise your gonna have to get a camber kit. this is how mine looks like ---
from my dealer -
falken502s 17'' - $270 on sale mounted + balanced. <-yay!
falken502s 15'' -$320 mounted balanced. <-nay!
SORRY IF THE PICS ARE TOO BIG :T
-jayson
