The bump vouchers we took were from AA in early Feb - they dont issue free tickets, always bump vouchers - no restriction on what you buy, other than they expire 1 year after issuance. As you see I applied them to the cheapie fare FLL/PDX at $149, $194 after adding fee and tax.
$200 is of low value as they only needed 3 vulanteers that time. It was last flight DFW/FLL, we came in from OAK, already pretty tired. So we took the offer + hotel + meal voucher. Could get another bump next morning (Saturday) but decided to pass.
lately people were getting $300 to $350 for domestic out from JFK, BOS, even PHL.... for only 2 to 3 hours delay.
The President Day long weekend, DFW to CDG was severely oversold, plus very foggy weather. I knew people getting 2 bumps in a row for $800 a piece with hotels and meals, if you were just going for a long weekend / mileage run ... $1600 total I would take it anytime. :-)
Each airline is different. UA only issues free tickets for example, vs AA only issue bump vouchers.