All three coins require basic conservation to optimise their potential, but all are nice detector finds. Individually, a dedicated numismatic auctioneer is unlikely to take them on. The tealby has an exceptional portrait, but is marred by the edge chip though it remains the most desirable. Dobunnic units in uncleaned condition may struggle to hit £50, I would see if it can be improved - most detecting clubs have someone who could advise, the aluminium foil/ alkali method often works well. If I had to sell, I would offer these for via Ebay or Facebook, set a reserve or price if you wish and see what happens. But as a long-standing detectorist myself I would say keep them, and find the upgrade money elsewhere - you will always regret selling your best finds.
Jerry