Hi Wuerstchenhund
http://www.go-dove.com/en/auction/view?auctionId=11018346
This one is a 204MXi but not the "a" version, whatever that is.
That is a WaveRunner (M)Xi, the predecessor of the Xi-A. It's a X-Stream I scope (PCI not PCIe based) and the predecessor of the Xi-A. It's a good scope but early ones suffered from a few quality issues that have been corrected later on in production and during service. The best indicator to see if this scope has the improvements is the handle, if it's blue (like the rear housing) then it has not been modified, if the handle is black then it has.
I think the "M" stands for math (additional math functions),
No, it doesn't stand for maths. 'M' is for scopes that are sold with the MSO option. Older WRXi did not have the L-Bus connector for the logic pods, only the WRMXi models had them (and if you retrofitted a Xi with L-Bus then it became a MXi, i.e. LeCroy also replaced the sticker). The Xi-A all have the L-Bus interface, however it is enabled only with the MXi-A models.
and I suspect the MSO option would be a pretty penny, as when you already own it, you have no purchasing clout with Lecroy.
How much purchasing clout you have depends on your negotiation skills, option prices are widely negotiable as are instrument prices.
The MS-250 and MS-500 logic pods are very expensive when bought new (the MS-250 costs some $3.5k but then these are roughly $18k scopes), but can occasionally be found on ebay for $1000 or less.
I tell you, It would take a lot of guts to lay down $5K sight unseen on a scope that may be a dud, with no recourse.
To make matters worse, these auctions come with no probes, cords, CD's, manuals etc.
Of course, which is why for the Xi-A in that auction I'd probably not go higher than say $3500, which leaves enough of a budget for having it fixed should it be necessary.
These auctions are always a risk, so you have to bid accordingly.