British Expats - hifx payments and other bank fees etc?

What the best method or least expensive method of paying you agent.
I have had an account with hifx which i thought was supposed to be less expensive than most banks.
Well i have used them several times for payment by bank draft to my tra agent,never checked or compared them to other banks.As was close to the xe.com conversion i did,so was more or less happy.

Well today i did the same thing to guide me on what my fee was in sterling,went and called hifx and was shocked it was way more that i thought.
Well it was not my normal way of using them as this was a transfer from my bank to there one,maybe they charge more for this method?
I then asked what it would be for a bank draft as done past few times,it was much less,so looks like using the transfer method was more.

I then contact my own back then they was less on the transfer from bank to bank method but more on the draft method which was weird,so looks like hifx was good for bank drafts,is this bank draft a cheaper option with hifx as i thought doing a bank draft would be much better for them and easy compared to a bank draft,unless they charge more cause its quicker.

I then have another bank which requires you to do it in the bank,a bit backward if you ask me when my main bank can do it online also,but this bank i talk about now is the flex account,does anyone know using that account to pay someone overseas is there a charge for doing that,im pretty sure there is not,they tell me not and i think i know from past purchases and payment i not been,so would they be right there.

Also i have the method of paying by credit card well this is not a credit card as such as flex account debit card,it states with my agent there would be a 3% to use a credit card is this cause i would be using a credit card or what they take off him that end,or just for using a credit card,what if i use my debit card?would there still be that 3%,even if i was i am working it out less than hifx and also less than my bank.

I know its several pounds here and there but the difference on them all is a bit of difference and at the end of the day,the agent will get the same amount but maybe me save a little in my pocket.

Any advise.