look here on Houzz. they were having a sale on rugs. maybe 5x8?

If this were authentic marble, you could go smaller, but since it's a fake Carrera pattern with some obvious pattern repeats, you should cover as much of it as possible, leaving only 18-24" around the rug. Choose something flat or low for the entry. Antique Persians are durable and hold their value, and go with everything. You could even do a "jute look" rug made out of something more durable than jute.

then look for a runner. they come in varying lengths.

https://www.houzz.com/photos/area-rugs/size_rug--2.5-x-10-Ft.-%26-Longer--3-x-6-Ft.-%26-Longer

Houzz has a sale on rugs right now from there newsletter, I do have to say I like that tile look you have!

Ken

they have a 2.5X10 on here for about 100 bucks. what prices were you looking at???

for instance, here is one for $57. I'm sure it's not superb quality, but it should be good enough. just look around at some of the other.s

Safavieh Adirondack Collection, ADR109 Rug · More Info

Safavieh Cambridge Collection CAM136 Rug, Silver/Ivory, 2'6"x10' · More Info

well if you click on the rugs, some of them have 10 different sizes you can order. you may get lucky and find one close to that width. like that last one, comes in a 4x6. I know it's not long enough, but most runners aren't that side. you actually need a 4x10 which is a large rug. that's why you will have to pay a bit more.

Have you looked at oval rugs?

Most carpet stores you can select carpeting and they will cut it to the size you need and then bound it. Some carpet stores have a remnant area where they will cut it to size, too. You may end up with some waste that you will have to pay for but you'll have the size you want.

This may be something to look into and see if it helps with cost and still gives you the size you want.

3x10, $300

Kaleen Casablanca Cas04 Rug, Ivory (01), 3'0" x 10'0" Runner · More Info