additional 10 cat 5 network points

The major drawback you'll have to take into consideration would be the limited bandwidth these 10 new points would suffer by going through a switch and then out to the same port on the main patch pannel through one line.

By going all the way out to the main patch panel with the additional 10 and elliminating the switch, everyone would have equal bandwidth to access the network (internal and external).

So, you'll have to decide which is best for your situation. Is the trade-off worth it? Is limited bandwidth (slower access for those 10) worth the minimal cost of stringing cable?

Running mainly CRM, Outlook, Internet...I don't see anything that is a major bandwidth hog.

Having 10 PC's share a CAT 5 line is nothing dramatic. You should be fine.

Since you mentioned a gigabit switch though, make sure the wiring can handle the full 1 gig throughput.

Then you should be fine. Sure, we can sit here and make all kinds of theoretical arguments, but for 10 people to share a gig connection shouldn't be a problem and I'm not even sure you'd notice any difference.

Unless you have 10 existing ports available you are still going to have to add an extra switch.

How would you add that extra switch to the existing location? Cross-over patch cord? Same difference, different distance?

Some network hardware allows you to multiplex ports together to provide increased bandwidth between two swtches. (e.g. combine 2 GB ethernet ports) We are currently using that here between the switches mounted in the main computer room.(qty 3) There are also 4 other switches at various locations throughout the plant. These are conected back to the main computer room with fiber.