Subtract the value of the pump from the cost of a new skimmer, then figure between 60%-80% of the difference. There range will largely depend on equipment age, condition and demand. ASM skimmers are usually in demand, but there are also a number of them for sale during any given month. If it is in good condition, I would think you should be able to get closer to 70-80%. Or you can wait and see what others are asking for them in the drygoods selling forum.
A G1-X sells for $256 new
Subtract $80 for the missing Sedra 3500
Multply by .6 and by .8
Result Range is $106-$141
You can might be able to go towards the higher end or above this range because of your mods. But of course, the lower the price the faster it is likely to sell. So you need to factor that into how long you are willing to hold out for your target price.
And you'll quickly find out if you asked too much or too little. Too much and you hear silence, too little and it sells three minutes after you've listed it. I've managed to do both.
If I were going to buy one, I know I can get a stock G2 for about $150-$160 with the pump so I probably wouldn't pay much more than $120. Your milage may vary...
