I believe so - the scope covered by the original discs is in excess of the £50 ones.

I say that as an owner of the £50 ones (£39 when I bought)

I would advise going on to Brakedwell's profile and hunting through his forums for a more definitive explanation

Can you expand on what you mean by that? In what way do you get 'more' with original discs?

I have just upgraded my September 2007 non-HDD system with Volvo RTI 2011.1 MMM P2001 P/n 31326246 and it all seems to be working fine. I can't see a lot of difference yet to the 2010 upgrade I did last year but I have done this mainly to make sure I have the latest roadmaps as opposed to any additional function.
Procedure was ignition on, Satnav on, remove the current disk (as shown on previous page of this thread), insert new disk and wait for the map of current location to appear.
Simples

I refer you to Klaiberp's posting on page 2 of this thread.

I seem to recall elsewhere something about these discs not having all European countries on them.

If I were a regular Euro-tripper, I wouldn't feel overly confident with the cheaper discs

Having spent a number of hours wandering through this maze I thought it might help others if I produced a short summary of what I believe are the two latest sets of disks available:

Pre-2009 models with non-HDD Satnav system.

Volvo RTI 2011.1 (MMM/P2001) Part number 31326246 (DVD) / 31337703 (MapCare)

Consists of 3 disks with coverage on each disk as follows:

Disk A: Andorra, Belgium, Channel Islands, England, France, Gibraltar, Ireland, Isle of Man, Liechtenstein, Luxembourg, Monaco, Netherlands, Northern Ireland, Portugal, Scotland, Spain, Switzerland, Wales

Disk B: Andorra, Austria, Belgium, France, Germany, Italy, Liechtenstein, Luxembourg, Monaco, Netherlands, San Marino, Switzerland, Vatican City State

Disk C: Austria, Croatia, Czech Republic, Denmark, Finland, Germany, Greece, Hungary, Italy, Liechtenstein, Norway, Poland, San Marino, Slovak Republic, Slovenia, Sweden. Switzerland,Vatican City State

2009 onwards models with HDD Satnav system

Volvo RTI 2011.1 RTI (MMM+) HDD Part number 31326248 (DVD) / 31337704 (MapCare)

Consists of two disks which after a few hours of loading onto the HDD provide coverage for all European countries, refer to the previous excellent post by GlynV8 for detailed installation instructions.

There are clearly a number of different ways to obtain these disks and hopefully this summary provides the basic information to seek them out and clarify what you should be getting.

GlynV8 has done it with the OEM Volvo disks but I think I see your concern. If you have some from a different source it would be difficult to confirm you have all the countries prior to loading it up without doing a file by file comparison with some OEM disks. For the HDD system If you have two disks then I think it's reasonable to expect you have all the countries so I would load it up and check them out by individually selecting them.
If I read this thread correctly it looks as if it is the non-HDD systems where some aftermarket vendors have been sending out only one of the three disks and thereby limiting the country coverage.

I agree - I not aware of any of the disks being modified/updated by OEMs. They are just copies of the original DVDs.

I did the upgrade with two DVDs (2050-01 (4.31 Gb) and 2050-02 3,68 Gb)). Both have a similar file structure: 6 generic nav sw files, including key file and loading.kwi file) and a Map directory where the Maps and POIs are located. Disc 01 contains all POIs and Region 0000 till 0003, Disc 02 contains Region 0004 till 0134 and Zipcode files.

Which regions are exactly covered is not clear on the DVD itself, but when loaded on the HDD you see all countries as shown on the Volvo website (so most countries of Europe).

If you Google those numbers you will see they are the 2010 discs not the 2011 ones.

I believe 31310191/31310193 have been available since mid-2010 and were superseded by 31326246/31326248 mid-2011.