I know this is an aircraft base antenna thread but I guess a UHF satcom antenna can be used as a UHF aircraft base antenna, so here is more info on pricing.
The more common Trivec-Avant 2040 series with two director element assys, a case, original coax assy in perfect condition is worth about $350. The same antenna without directors which makes it a two element cross dipole over reflector is worth maybe $175-$200 in well used condition. The D&M version would be worth a similar price and smaller lightweight versions a little less. The huge D&M base version that is about 9ft long with tripod is worth roughly $700 plus or minus depending on condition and if it has the transport case.
Most people ask way more than what I quoted and my prices are from current dealings with people in the mil radio hobby and selling a bunch of my stuff recently. In the end, supply and demand drives prices and if there is nothing for sale for a long period of time, the first thing that comes available will usually go for a lot.
With that I have sold a Trivec 2040 series for upwards of $700 and a magnetic X-wing version for $900 to a mil contractor that couldn't live without them. A few weeks before selling the X-wing for $900 I had picked up two of them on Ebay for $35 each.
Now back to aircraft base antennas and I would recommend the OP watch Ebay, sometimes surplus airport antennas come up for reasonable prices and they would cover the entire 118 to 136MHz range. Look for brands like Antenna Products or TACO or sometimes DB Products for the fiberglass types and Antenna Specialists, RAMI and a few others for ground planes.