WISE move IMHO!

Had a look this morning and walked away, it was from a corporate venture so used by novices and crashed twice and badly repaired the front had been bodged up with I assume a Isopon P40 kit, the top deck wasn't too bad but as soon as you lift the skirt there's nothing bonded to anything.  The other damage was on the side ( see picture), again looks like it's slid into a post or whatever and that repair didn't look to healthy either. I didn't look at anything else as that was enough put me off, I dare say you can repair it properly but why (knowingly) buy a headache when for an extra 1K you can buy one that's sorted.

looking carefully at the photos, I would say it's been driven into a something and been repaired, we'll see.

Ian, thank you for taking the time to write this, I will report back after I have seen it.

Electrics are a favourite issue. Look for non-sealed connectors such as bullets and spades, the wire corrodes and fatigues where it enters the crimp. They will probably be bad. Even if good, unless they are fully sealed you will finish up replacing them.

Check the skirt - looks like some segments are loose. Check the lower attach points, they've often been knocked off. Wear on the segments is likely.

Check underneath, there can be severe wear if the craft has been used on a hard surface, eg car park.

Check for repairs to the hull, typically caused by inexpert pilots hitting posts and the like   Often badly repaired.

The fan hub should be checked carefully for cracks. Depending on the year, they were running the fan very fast causing fatigue failures in the hub. Not so long ago we checked 3 Marlins and two had this problem. Newer Marlins run the fan more slowly which has resolved the issue.

If this has the moulded fuel tank then check for leaks, ethanol in fuel seems to denature the GRP, in older craft this was a problem for a while, If it has boat type tanks it'll be ok.

When running the craft, have someone rev it up whilst watching the belt track on the upper pulley. If it moves about on the pulley as the power comes on, it suggests something is deflecting in the fan frame. In extreme cases the belt can come off. The belt should track in the middle of the pulley and move only a little as the power comes on. It shouldn't run hard up against the pulley edges. Obviously check the belt for fraying and wear.

Check the engine for corrosion, especially the coil packs. You may need to take the front cover off to see them, they are often badly corroded.

I would make a list and tick them off as you check - otherwise excitement can lead to a duff purchase. Don't ask how I know this 

That's probably enough for now!

I'm off to look at this tomorrow any advice as to what to look out for? I believe it's a 2012 model for £3k. TIA