These guys are correct - bakers yeast will not go to such a high percentage as a wine or specialist distillers yeast. However, like they said the higher percentages have their own issues.
It's all proportional as well - for example, imagine that 1kg of sugar is £1. A 25 litre bakers yeast wash might include 5 bags of sugar, some bakers yeast, splash of lemon juice and a bit of tomato paste. Total cost maybe £5.50. It'll only ferment to say 11%, so assuming a loss of 1 litre in racking you'd have 24 litres at 11%, or 2.64 litres of 100% alcohol if you discount the water. This works out at £2.08 per litre of ethanol.
Now imagine another wash with a specialist yeast - the yeast may cost £3 and go to 18%, and require six bags of sugar. These kinds of yeast tend to contain their own nutrients, but you may need clearing agents or carbon so we'll add another £1, so say £10 in total. The yield will be 24 litres at 18%, or 4.32 litres of 100% alcohol. Cost is therefore £2.31 per litre of ethanol.
I made up the starting figures but they're just an example. My point here is that the alcohol at the end is basically the same stuff, so the choice comes down to your own priorities - the first method works out cheaper ingredients wise, but takes longer to ferment, means more distillation runs, etc. The second method is more expensive on paper, but your time may be more valuable to you and you may consider it worth the cost. Personally I'm in no rush, I don't have access to a local home brew shop, and I prefer the taste of the bakers yeast. You may find different, but I hope this helps!