There are a range of types of ways to receive money, if one has views which are sympathetic to Russia, and unsympathetic to Nato, Ukraine

Somewhat more legitimately (or legally at least), eg by £ for media channel appearances, eg by Farage

And illegitimately, eg unlawful bribery in case of Gill.

It would be useful to see a detailed comparison of what Gill said (as a result of bribery) and what Farage said, on the same topics. It is perfectly possible he made broadly similar arguments from conviction, rather than for money, though they can be criticised as bad arguments.