At a nominal 28-29 feet you will floorplans with:
No slides, fore-aft short queen bedroom with nightstands and shirt closets, or maybe one small full length wardrobe, split bath, kitchen, and dinette and jacknife sofa opposed, usually no aisle when sofa is out, sometimes making up one big up front bed. This is the typically rental 28 footer, for most of the past 10-15 years almost everybody made one. These are useually non basement, with smaller outside storage bins.
One slide up front, 8-12 foot depending on whether it holds sofa or dinette only, or also includes part of the kitchen. Front slideout provides enough room to maintain an aisle between dinette and open jackknife sofa, or permits sofa alternatives like hide-a-bed or powered loungers. I see this in more B+ floorplans than in C, particularly if the idea is to accommodate lounge seating. A variation on the theme might be a big U-dinette in the slide, or opposed sofas with no dinette.
Two slides in this size, one up front, one in the rear, usually with an East-West queen. Slide in the rear makes space for a big rear wardrobe. Slide can be either side, might contain either the wardrobe or the. head of the bed. My Winnebago/Itasca 29B is an example that might be in the year range that fits your budget. Friends had a Sunseeker with almost identical layout, but traded it after three months for an Outlook 29B, said the Sunseeker didn't live the same as the Winnie/Itasca, but I didn't appreciate whatever was the difference, not having the experience of trying to live with it. Those two I know about, other manufacturers have done variations in nominal 30 foot sizes.
Slideouts buy you more than just floorspace in a C this size, at least on E-450. To put the front slide mechanicals under the floor, floor will be raised 6-10 inches higher over chassis rails, creating room for water tanks and such as well, pass-through storage space, and making for taller outside storage bins. Downside is 500-1000 pounds extra weight for slideout room mechanicals and slideout box structure. Space to carry more, not necessarily capacity to use the space.
Nominal 28 footers tend to be over 28, sometimes almost 29, on Ford chassis. Same for 29s, mine is 29'8" bumper to bumper. Same model on Chevy (which wiil usually be non-slide 28s or someting shorter in 1998-2004 model years) can be about 20" longer than the E-350/450 build. Tha's cab length, and it buys you space in the cab. But it means a "28 footer" that is not quite 29' on the Ford could be over 30 on the Chevy.
V-10 as E-350 does not tow as much as V-10 in E-450. There are gearing, axle, brake, suspension differences that lower GCWR of the E-350. Still maybe better than the 3500 tow rating Chevy put on G3500 cutaway in motorhome use, regardless of GCWR on the chassis.
Tom Test
Itasca Spirit 29B