Software for creating large Photo Collage Posters

I have been asked to create a 20"x30" poster with a collage of photos from a recent event. Mpix prints at 250ppi so I need to make a 5000x7500 pixel poster. I don't currently have any software up to the job.

Any recommendations

I currently don't own any Adobe products (and don't want to spend hundreds of dollars) and I think the learning curve on Photoshop would make this a longer project than I want. I also don't know which of the adobe products I would need to do this.

Any suggestions?

Free: Gimp. https://photography-on-the.net/forum/showthre​ad.php?t=683358
Not too expensive: PS Elements.
Other options: PaintShop Pro, and probably a lot of others.

Do you use Windows or OSX?

PS Elements, but it will take time to learn, especially a collage.

Thanks for the info. I use Windows 7.
I did download a trial of paintshop pro.. even this seems to be taking a while to learn.
I created a background layer, then a raster layer and copy/pasted an image onto that, but now I can't figure out how resize or position it.

It looks like it can do what I need thought.

Gimp x2. I did a hockey collage last season for our coaches.
24inches x 36inches at 150 dpi. (3600 x 5400).
150dpi was the lowest resolution he recommended for photos.

I used GIMP and bunches of layers. Turned out great.

I am also trying to do this, not a collage of random images but more of a "grid" pattern of various sized images to be made into a poster perhaps 24x36. The newspaper I shoot for uses Quark to do this but it is too expensive for my uses, I am currently using Elements-9. Any ideas?

Thanks for the ideas. I tried Gimp and a program called FotoFusion. It looked like Gimp was going to take some time to figure out (more time than I had). I used a demo of FotoFusion.. Designed for yearbokks and expanded for general purposes, this seems like it is the best package for this sort of thing, but (I think) the trial version was hobbled -- I could not easily figure out how to start with a 7500x5000 pixel canvas even though the package claimed unlimited resolution (and another person showed me some work he had done with it). Outstanding package, but for one little project I was not prepared to shell out the bucks for it.

The trial version of PaintShop got the job done, and at $60 -- I will purchase the product. Thank you René!

One of these days I will breakdown and purchase PhotoShop.

Anyway, here is what I ended up with after just a few hours with PaintShop, The original was done at 7500x5000 pixels for a 30"x20 print using a 250dpi printer; this copy was downsized with trademarks obfuscated.

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