In regards to researching wholesale prices you would be better off contacting the suppliers in person, either walk in or by phone. It's a sad reflection on customer service, but there are so many businesses today that treat email inquiries as second class inquiries. The adopt the theory that if you are serious, you'll go to them or do business over the phone, so emails get pushed to the end of the line, and then sometimes ignored altogether.
You'll usually find that once you have an account established you will get an account manager, then your email inquiries are usually treated with some level of priority, at least they should be. If they're not, then you're doing business with the wrong company.
Personally, I would think twice about dealing with any company that treated my email inquiry with complete ignorance and look for a company who offers a higher level of customer service straight off the bat.
Either way, you really would be far better talking to the supplier in person, that way you can get an accurate price based on the load size you are looking at buying and then have volume discounts factored into your business plan in accordance with your projected business growth and so on.
Cheers