There are no pure income requirements when claiming someone as a dependent - the main requirement is that your parents need to have provided more than half of your support for the year. Since they paid $22k in education expenses and you only made $20k, certainly they paid for more than half of your support (even if it were less, they could claim that they provided housing and food as well)
So yes, they can claim you as a dependent.
That said, the main difference is that the personal exemption for you ($4,050 for 2017) will count towards their income rather than yours. That may be a better deal for the family overall since your tax bracket will likely be lower than theirs, but that's between you and them.
how much tax return should I anticipate?
You'd need to complete your full tax return to be certain, but a VERY ROUGH calculation would be
- standard deduction $ 6,350
taxable income $13,650
tax = 932 + 15% * (13,650 - 9,320)
- withholdings $2,821
= refund $1,240
If you claimed yourself as a dependent rather than your parents, your taxable income would be $4,050 lower, giving you an additional $607 refund (4,050 * 15%).
However, since your parents provided a majority of your support, it's perfectly reasonable for them to be entitled to the tax break.