I'm aware of Greenbikekit. Their pricing is ca. $4 per terminal plus ca.$8 p&p. for several items.
via Aliexpress ca. $0.67 plus ca. $5 each p&p.
Both subject to 20%vat
So similar costs if I was to buy 5, but both end up costing £6 or £7 per terminal with an intrinsic value of a few pence.
Some enterprising Brit may (or should) import, sell them for a couple of pounds with a good profit margin and provide a service for those of us with these batteries... I've charred two of these terminals while riding 31k km overe the last few years.