drooping
You can absolutely buy compression shirts for less than $100! (unless the reference is to a medical grade item).
You can get Under Armor or Nike for about $30 each. While the quality is not quite as good, you can also get the C9 brand at Target for $12-$18.
I only wear then when I run, so I am not sure how comfortable they would be wear all day, but they are great during exercise.
I wear UnderArmour Compression shirts all day, every day. When I run, I also wear compression shorts (like bike shorts) to keep things where they should be!
The compression shirts can be a bit of an investment up front, but IMO, they are worth it. I just bought two of them until I reached my final stable weight. I just keep washing and reusing them during the week. On the weekends when I wasn't going out in public (and to work) I would do the "one size too small wifebeater" thing like previously mentined.