£50 a blackface lamb is not cheap, its what I would expect to pay for a maternal bred lamb really, actually I would pay less for a blackie lamb right now
Good terminal sired fat lambs at market are making £60 at the moment!
maternal bred lambs would make far less than this at market right now, may make £50 as stores later on
Look at what all your neighbors have and look what works in your area, would give you a clue as to what to get

For a smallholding I wouldnt generally recommend blackies, they are thrifty hill sheep that produce mainly one lamb and aren't generally kept on smallholdings.
If it was just 2.5 acres then perhaps something that you could make the most from, so something that you could stock higher and rotate in small areas (strip graze?) rather than a large ewe, so you could get more kgs of lamb per acreper acre
Or get a larger more commercial ewe and have fat lambs away earlier on in the year (lamb in march, away in June off grass) and then just dry ewes to live off nothing rest of the year
I have welsh mules which are very very easy to handle, nice and friendly, stay behind one strand of electric, they lambed in march/april and first batch of lambs were 40-45 kgs in June off entirely grass
They also arent too expensive to buy in and have a high cull value
Shedding sheep are ok, my ones (exlanas) have been bred for no foot issues and no lambing issues etc, very very easy care, however I rent my land and they do cover (smother) all the fences in wool, which landlords tend not to enjoy so much.......