I wouldn't get a high chair for a nearly three year old. Instead, I'd suggest a Stokke Kinderzeat. They don't have a five point harness, but I haven't found that to be an issue. Both of my kids use them, and we don't even need to buckle them in anymore.
A cheaper version than a Stokke high stool is at One step ahead for $99
http://www.onestepahead.com/product/85205/409757/117.html But I'm sure if you shop around, you can find other knock offs. It's a chair. As long as its sturdy and comfortable, don't fuss about it.
I'd either go with the Cooshie booster or a high stool, especially if the child is over 2. As soon as she could sit without support around 9 months, my daughter HATED being strapped in any traditional high chair. Graco or Peg Perego, it didn't matter. She went from adorable and ready to dine with us, to battling against being harnessed and padded chairs.
I picked up a really cheap Hauck stool similar to the one in the link with a wood band around the waist area and a simple strap linking the band to the seat for about $30 for travelling. She loved it and has used it ever since.
At 2, I was able to take the band off. She climbs up and down all on her own. Promotes independence, as far as I'm concerned. Not babyish at all. But don't ever make the mistake of asking her to sit in her
chair -- "It's a STOOL, Momma!" She's three now and very proud about it.
We had a Cooshie and she enjoyed it for a very short while when we were out of the house. (Sold it on ebay and the buyer loves it.) Now she prefers sitting like an adult or on her knees. When offered a booster in a restaurant, she always says "No, thank you, I like to sit".