Most would agree that if it is a MISR-90, which is a Century build using parts from a Norinco MAK-90 on a Maadi receiver, stay away unless you get it dirt cheap and can test fire it.
The Steyr imports are considered the only true pre-ban Maadis and currently are selling for $1500 and up. Be careful to make sure that it is a true Steyr as I have seen one fake that the seller had stamped "Styer" on it.
In post ban form, the ARM is the most desirable as they still had threads on the muzzle. Current prices run from about $600 used to near $1000 for one new in box.
Next is the RML, which was similar to the ARM but most did not have threaded barrels. Prices for the RML mirrors the ARM these days.
The long barrel version is the RPM, but there are a few long barrel RMLs running around. Many people like to install a club foot stock to give it the RPK look.
At the lower end of the good Maadis are the MISR S/A which were nice rifles, but imported and converted to 922(r) by Century including their trigger slapping fire control group. My personal price range for a MISR S/A is $400 to $600 for new in box.
There was also a MISR-10 which had a single stack mag well to allow it to be imported per the sporting purpose clause of the new ATF second amendment. Century, the importer then opened the mag well in country and with it the conversion to the Century made parts. Most were ok, but many were like the WASR-10 with mag well issues. I can't give you a good price range for these other than like the MISR-90, darned cheap.
It that picture is the actual rifle, it is hard to tell if the wood is original or someone refinished it and installed a top cover with the scope mount. If it comes with the original cover, and the wood looks better than the picture, it looks like either an ARM or RML, so if you can get it for anything under $600, I would go for it.
Pass on a Century gun, look for a PARS Lou KY or Intrac A.C.C. Knox TN import.
If it has a US receiver then it's a kit build and You could do that yourself for less than most want to sell them for while ensuring quality in the process.
Some barrels are threaded with a removable sleeve tack welded to the FSB. These are worth more than those without. Some may even be turned down, I would pass on those.
3rd Y will make it a tad more authentic and raise the value.
Easy to deban with a GB, FSB, slant brake, pistol grip and stock. I have several of these (and bayonets) if you want to PM me.
You could take it a step further and replace the selector stop with a short one. Would be ideal if you wanted to have the selector markings redone.
A real preban Steyr will cost you what a Poly Tech Legend will. There were also a few imported with the crutch folder and an ugly grip that are preban but I don't believe they are Steyrs. I'll have to get back to you on that.
I have seen several post ban examples with all the desirable features sell for $600-$800 in the last 6 months on Funbroker.
Some double stack MISR's are all Egyptian, some were single stack and some were Mac 90's. I had a MISR that was double stack, all Egyptian and it was a nice piece. Without better pics of the rifle, the magwell, and anything else- it's hard telling.