I didn't do a "market research" hunt to see if heads are available at a better price, but the price shown (£81.25 inc vat £69.15 ex-vat) would almost cover the cost of a new multipurpose machine (List Price: $199.99, Used: from $125.50 for MP390).
A quick read through Reviewer Comments at Amazon indicates that print head problems are common with this particular printer. (Several other brands/models are similarly afflicted, and the problems are common to most printers that use "fixed" heads.)
Newer printers in the same price range generallly have the "print head" nozzles built into the ink cartridges, so each new ink cartridge gives you a new print head. This method also eliminates the "tubes" that carry the ink from the cartridge to the head, and the tubes also can sometimes clog and give the appearance of a clogged head.