MUFC Fan,
What difference does Russia make as opposed to another non EU destination or, indeed, former FSU destination!
The 'orange' brigade do flights UK to (non EU) Turkey, all inclusive, for circa £31.00, a one way fare from LGW to KBP (Ukraine) with UIA is:
Fare per person 58.00
Taxes & Charges 52.20
Ticket issuance charge 3.00
Totals 113.20
The only tax penalty out of UK might be for flights from/to LHR where there's something like a GBP50 tax, other than that it makes no difference where the destination may be.