start at +8k and depending on response drop price by 100 ped decrements or so every week.
Why ? If you do not get offers at +8k it is obviously too expensive. At some you will reach the price people are willing to pay.
If you already got offers for the +8k i think you wouldn't have opened the pricecheck thread, so the odds are good you got some lower offers via pm. Probably you are not sure if these are reasonable offers. With this strategy you can circumvent that and at some point you will find someone willing to ppay the price.
In my opinion that will be around +7k maybe a bit higher, but not by much. But that is only an assumption and i can be wrong here.