It’s April, and your customer wants you to quote a catalogue for them.  You take your time, send out the quotes and get numbers.  You send them the quote two days later.  If you do not see or hear from your customer within a week or two, you should most definitely be following up with them.  They may have someone else quoting this job as well, which is ok, but what’s important to remember, that it may not always be about the numbers you send them, it may be about the relationship you have built with them.  If you follow up, discuss pricing, and make sure the customer (or future customer) keeps you fresh in their mind, or you have done something to stand out from the other people quoting it, you have a better chance of getting this one job, but also repeat jobs in the future.
So when you send out a quote, following up, is more about just getting the job, it is also about building a relationship with a customer for all future jobs you may work on with them!