Bought a gammon and sliced it for sandwiches. Saved 62 quid.
Joint was a 2.5kg smoked Wiltshire cured gammon from Tesco @ £6.25 a kilo clubcard price. Equivalent sliced ham @ £31.25 a kilo would have cost 78 quid.
Cheaper ham and cheaper gammon are available, but a similar price ratio applies whatever your price point. I prefer to pay a bit more because of the higher animal welfare standards.
The game changer for me was cooling the gammon for a while in the cooking liquid, then wrapping it up tightly and putting weight on it overnight in the fridge. Made it much easier to slice thinly.
Cooked in the slow cooker for 6h with carrot, onion, celery, garlic, and pepper. Cooled in the broth for approx 1h. Removed and wrapped tightly in greaseproof then tied with twine. Wrapped tightly again in foil. Plate on top with some weight (couple of tins) then in the fridge overnight. Broth strained and saved to cook beans in.