Personally, I'm a bit of a cheap bastard, so I'd give it a go with the available goods.
Like I said previously, the yeast being a bit stressed might lead to some minor imperfections in the brew, equally possible that they might not, then, leaving the brew in primary for a good few days after reaching FG for them to clear up some of the by-products you'll more than likely end up with a perfectly good beer.
Giving the yeast absolute ideal conditions in a starter will just make them do an even better job during the fermentation round and mean, as long as good fermentation temps are maintained, less probability of off flavours and smells needing cleaned up.
In the end, it's your call. Only you can really assess how much more than the recommended amount of DME you used for your starter.