I use the starter with weed preventer in my lawn for fall seedings because I have a lot of broadleaf weed pressure coming from a neighboring property that does not control its weeds. Here in MN, by the time I can spray the new seedlings it's really too late in the season to effectively get those weeds and I'll be stuck with them through a good part of the following spring.Take a look at Scotts "Starter for new grass with weed control"
If it seems pricy --at about $38--you are right. It contains mesotrione--better, it kills crabgrass. and it costs more. Covers 5000 sqft.
Probably you can get by with the ordinary starter fert with no weed control in the fall.