More important to have a look at the information sheet or similar for each product. On Finspreads as an example, it states 'Bet per': for the Dow, 'Bet per' is 1, so a long of £1 per pt at 11,000 equates to a position of £11,000: for GBP/USD Rolling, their 'Bet per' is per 0.0001, so going long at current price of 1.4933 at £1 per 0.0001 equates to a position of £14,933.
Of course, we've all got these things wrong at some time and ended up with a position ten times too large (or small).
Interesting that Fins refer to Dow SB offerings as Wall Street, which is not silly, as you are not spreadbetting the Dow, you are spreadbetting Fins' quote for a Dow spreadbet.