Not sure how big of a tea pot you are looking for, but Stash Tea has a ton of lovely sets in all price ranges. I hate the way their website is set up, you have to click on things to get the price, and I can't find my catalog.
Here is one tea pot (not for stove) that holds 20 ounces and is $13. The mug holds 8 oz. and is $5.60.
http://www.stashtea.com/products/Chantal+Berry+Red+Personal+Teapot.aspx?category=TEAPOTSCUPSMORE
http://www.stashtea.com/products/Chantal+Indigo+Blue+Tea+Mug.aspx?category=TEAPOTSCUPSMORE
The Curve set you can buy individually in several colors, orange, green, red, sage, turquoise and white. The tea cup doesn't have a handle, holds 6 ounces, but it is $5. The pot holds 40 ounces and is $28.
http://www.stashtea.com/products/Curve+Mandarin+Tea+Cup.aspx?category=TEAPOTSCUPSMORE
http://www.stashtea.com/products/Curve+Red+Teapot+with+Infuser.aspx?category=TEAPOTSCUPSMORE
Also, look through Stash's clearance.
Here is a beautiful tea pot (18 oz) and set of 4 tea cups (3 oz. -meant for sipping) that is $26.99.
http://www.stashtea.com/products/Geisha+Tea+Set+for+Four.aspx?category=CLOSEOUTS
And here is a Yellow set, mug holds 12 oz. and is $3. Pot holds 22 oz. and is $18.
http://www.stashtea.com/products/Tokyo+Stout+Mug+by+Chantal+Yellow.aspx?category=CLOSEOUTS
http://www.stashtea.com/products/Tokyo+Teapot+by+Chantal+Yellow.aspx?category=CLOSEOUTS
I think that you are going to be hard pressed to find a new tea set for $25. Essentially, that is $5 a cup and $5 for the pot.
What about you buying a pot and asking each of the girls to contribute $5 for a cup?
I love tea. Now I need to go turn on my water pot.