Great, thanks for your considered reply j_menz - I'll go with the cheapest one for now to get me started, and start saving for something a bit more professional!
If you're a total beginner then these sort of keyboards are a great way to start. Theyre certainly not 'toys'.I cant afford a piano and have no room yet. My keyboard is similar to the panasonic in layout-its a Yamaha PSR225 which I bought new in 1999 solely for the great piano sound and touch sense. The minimum you should have on a keyboard is touch sense if you intend to learn piano. If you're still interested in years to come you can progress to a DP or an upright piano.One thing missing from these keyboards however is the weighted keys. They are organ keys, merely on/off switches, compared to piano keys which are levers.Theyre a great start though and there are loads for sale cheap on ebay!
I still don't see its right to call such keyboards toys. Some yes, not all. And if you can't afford or have room for a piano but need to play they fit the bill until your circumstances change!