Managing toddler expectations/I kind of screwed up a big-boy bed gift plan

My son's 3rd birthday is coming up and I wanted to get him a car bed as part of his gift. I found one on Craigslist for $100 -- a blue sports-car one that I know he would have been really excited about if it had just appeared in his room one day as a surprise. But for some reason (I can't remember the rationale), instead of just getting the blue car bed as a surprise for my son, I decided to browse car beds on Amazon with him, asking him which ones he liked. He spotted a Jeep bed. His heart is now set on a Jeep bed. We can't afford it and it's too big for his room. But now it seems like the blue car bed would just be a disappointment instead of a fun surprise. But then I think, he'll have to get used to us not always being able to afford his number-1 choice, and we're going to get him other b'day gifts, so maybe I'm overthinking it. What do you guys think? Would it be worse at this juncture to get the blue car bed despite it very clearly not being the one he picked, or to scrap the car-bed idea and chalk it up to a bad play on my part?EDIT: To be clear, I didn't go so far as to promise him the Jeep bed or even tell him we were going to buy a bed at some point soon. But the idea was pretty unambiguously to look at beds he might like to have someday... via /r/Parenting http://ift.tt/2cXsEiR