Calling all bargain shoppers!!

Ok, guys, I have a question that could really use your input. Here it is: Is it ok (and by "ok", I mean, not completely tasteless and tacky) to buy some of William's Christmas gifts off Craig's List/Ebay? I bought a kitchen set for Wip off Ebay for his Birthday, but it was brand new and in the box. Recently, I found a toddler basketball hoop on Craig's List for $5 in like new condition. Most of me wants to just go ahead and get it and give it to him now...but I do that with EVERYTHING and then nothing gets held until the holiday! That got me thinking, is it tacky to get it, keep it hidden, and have it under the tree as a "Santa gift"... already put together and ready to be played with? I know he's only one and could care less, but to be honest, I don't want others to be like, "she yard sales her kid's Christmas stuff?!"....see, I do care what you, and others, think!!