Want to start rose business

Hello in the first place. I have no idea how stupid this question may sound to you or questions i will ask in the later post, as I've got zero experience and knowledge about flowering and how flower business works.
To be begin with, I would like to say that me and my friend ( both 19 years old) want to start some rose business. We don't live in a big country and in the capital city where we live, is only one flower store ( pretty big but still it's just one)and the owner of this store is my granfathers friend. I was just looking for rose seeds on ebay and noticed that they are really cheap to buy. I have big place in my village where I can plant them and later on when roses are ready i will ask granpas friend to sell them for me. Sounds idealistic I know, but the problem is that neither me nor my friend knows how to grow a flower, but I will actually learn how to do it thanks to internet. So my main question is ( which may, i repeat, may sound stupid) how many roses can be grown from one seed ( as I've noticed that you can buy several hundred seeds under 10$) and what are the best selling roses?
In addition to my story, I'd like to add that I am not poor or anything, I just want to make something on my own, to start a little business which will come in a hand after with my future job, when I graduate from university.
Thanks in advance and sorry for my english

Congratulations!

First, I'd suggest you read the posts in the Seed Germination Forum here on DG.

I don't have experience starting a nursery business but I do have experience starting many other types of businesses.

My suggestions are:

Learn what roses grow best in your region.
Learn what roses are most popular in your region.
Find out what local regulations and laws nurseries must follow.
Learn about the restrictions of buying and selling seeds internationally.
Find out where you can buy local seed. For inexperienced shoppers I do not recommend buying from eBay unless you know persons who have bought from a particular eBay merchant before.
Watch the seed trading and international forums here on DG. Occasionally you may find people with rose seeds that are willing to send them to you for postage only.
Avoid spending money on hundreds of seeds before you get more experience. You can save the money for later.

The best learning comes from experimenting yourself.

Buy a few rose seeds of the different types of roses that you decide you want to grow.
Try growing them at home. This will give you first hand knowledge about seed care and possible germination rates.

Best of success in your new venture and above all do not get discouraged or allow others to discourage you from reaching your goals.

Once you have seedlings started, there is a Rose Forum where you can ask questions.

In addition to learning how to grow roses, you also need to start learning the basics of running a business. Purchasing, inventory management, shipping, and cash management, basic bookkeeping, and possibly human resources, are all areas that eventually you will need to have a good understanding of.

Hi Misho
There are many kinds of roses. Some are bred to have long stems and look good in a vase. These are sometimes called 'cutting roses'. They are the kind that a flower shop sells for bouquets. Your seeds could be any kind of rose. Roses are shrubs, and some of these could take 2 or 3 years to bloom. Some roses only bloom once a year for two weeks, and some bloom all summer.
What most people do is to take a 'cutting' or 'slip' which is just a little branch, and stick it in a pot with soil. Often it will grow roots. That way you know exactly what kind of rose you have. With a 'cutting' the new shrub is exactly the same as the parent. With seeds the new shrub could be a lot different. This could be fun, or frustrating that it took so long to find out you have the wrong kind of rose.
Note- "cutting" has these 2 different meanings in English.