I'm a novice at this myself, but I have a feeling that some on this forum would advise you to look for something that fits you better and is a little older. (Fortunate that you posted this in classic/vintage.) For $450 you can probably get a pretty good bike from the 80s/90s in good shape. Also, larger sizes tend to be harder to sell, so on average, prices will be lower than the same bike in, say, 54 or 56cm.