It means that they flow practically the same amount of fuel as the LET stock ones.
But if the price you were quoted for cleaning has vat added to it and postage and all, then the new Wallace injectors are not a bad alternative. They'll be new, after all.
Get a flow test done first, and just get the ones cleaned that are under flowing. You'll also be able to spot any leaking/sticking injectors too. There's no point in getting new unless there's a problem with your old ones really. Get them checked out first