On a £100 deposit (which is more than I usually deposit) and assuming a withdrawal, that's £4.75 in fees vs. zero (at most casinos) if I use my card. Bear in mind that I'm Scottish and therefore genetically required to be a tight-arse; I blew a £400 balance at Videoslots the other week because I didn't want to pay a 3.9% withdrawal fee.
But that's not how you have to do it though, like I said, as long as you're not averse to keeping cash in Neteller from one session to the next at different casinos,
just leave it in there and you don't pay a penny in fees to re-deposit a withdrawal from one casino into another.
For example I had those two cashouts recently from Platinum Play and Mr Green, most of which I've withdrawn from an ATM but I left £120 in my Neteller account as I knew I was going to be playing the 1st and 6th of the month VIP matches at 3Dice. (An £80 and a £40 deposit.)
The fees on the withdrawals are far easier to absorb because you can work around them and by definition you've probably won anyway, so I'll often try and withdraw a round figure plus £3 from a casino, to cover ATM withdrawal fees from Neteller.
Now admittedly the 1.75% deposit fees do add up over time, but looking at my online spreadsheet - (which tracks money into Neteller and money out, but doesn't record movement inside the casino ecosystem because it doesn't care about that, ultimately I just want to know how much I've deposited and how much I've withdrawn as that gives me my overall profit/loss) - I see that I've paid £293 in fees for deposits in the last 21 months, which I don't think is unreasonable. (I don't count the £3 withdrawal fee because that's deducted by Neteller, I just record what I actually get in my hand out of the ATM.)
And there of course the idea is to, where possible, withdraw bigger amounts, as they charge £3 whether you withdraw £500 or £100, so trying to work towards a bigger withdrawal where possible is obviously the way to go. As long as you've got some self control and don't mind having cash sat in Neteller, occasionally for a reasonable period of time, it's no problem.