Should I replace my iMac with a Mac Pro as a high school video editor?

Hey everyone this is my first post and I wanted to get some opinions. Currently I'm 16 years old and I have a 2011 base iMac with 12gb ram that i purchased a few months ago. I edit lots of video on adobe premiere pro cs5 and after effects cs5 for school projects as well as a youtube channel and other various projects. I use a canon rebel t3i, which shoots full 1080p video (obviously eats up hard drive space very fast). My iMac works well enough for right now...has crashed a few times but it does the job. My only concern is 1. Hard drive space 2. Speed decrease over time 3. no customization. So because of these concerns I have been looking into getting a 2008 Xeon dual quad core Mac Pro to replace my iMac. It would cost roughly what I could sell my iMac for (craigslist) so I am wondering if it is worth it. Although the mac pro is a couple years old it has a possible 32gb of space for RAM, 4 hard drives bays, and 8 processors compared to 4 in my iMac. My iMac has 500gb and i only have around 80-100gb left after owning it for only a few months...and I feel like it's going to be a pain to buy an external hard drive as a scratch disk. Is upgrading to a Mac pro worth it? I feel like it would really be a good idea since it would be faster (8 processors and 32gb of ram on premiere would be a breeze) and lots of options of customization in the future like hard drive and video card upgrades. I have someone interested in buying my imac and someone interested in selling me their 3ghz dual quad core 2008 mac pro. Is this something you guys think I should do? I would love to hear any and all opinions.

G'day and welcome to the forums.

You have summed up the advantages of the Mac Pro. Four hard drive bays, and after that the second optical drive bay can be utilized. Additional memory never goes astray and of course you can upgrade the graphics card to the later ATI Radeon 4000 and 5000 1GB versions.

The 2008 Quad Core machine is a pretty mean beast in its standard form. For what it is worth the 2011 iMac and the 2008 3GHz Quad Core Mac Pro have nearly identical Geekbench scores, 7,926 for the iMac, and 8,166 for the Mac Pro. And one of the biggest pluses for the Mac Pro is a fast 22X optical drive which is a tray loader.

Slot loaders fitted to MacBooks, Minis and iMacs do seem to have a high failure rate.

You have a storage problem...You must be backing up your current HD correct...? You need to invest in another external and use it as a scratch disc or transfer your completed projects and final renders to it....You can't keep devouring HD space on your internal with these files. That needs to be addressed first.

I would implement some strategy before any purchases.

Rather than considering "an" external drive for your iMac, consider a Thunderbolt-based RAID array. Using a RAID Stripe-option, you'll get 2-4 drives acting as one, and with very fast transfer rates over the Thunderbolt connection. Unfortunately the 3rd party options for Thunderbolt are pretty sparse, but Firewire 800 will be a next best thing. It also won't be cheap, but even if you get a Mac Pro, you still have to contend with getting new drives. Here's one example of a 2-bay RAID box:
Mercury Elite-AL Pro FireWire, USB2, and/or eSATA RAID-0 up to 4.0TB Plug & Play Solutions

EDIT: One last thought… in lieu of using Firewire 800, you could use the eSATA option on that above-linked RAID device and get an an adapter or "breakout box" to use the Thunderbolt connection.

From what I can tell, you might need a more powerful computer and the Mac Pro sounds more powerful. But you should not worry about the HDD. It is always an option to get an External HDD with lots of memory for a good price. You can get like a 3 TB for about $150 - $200 I think.

But if you think you need a more powerful computer, the go for the mac pro.