You did a nice job on that. I have one similar to what you have and I really like the way that it cools my wort. I think that you will be pleased with what you have.
It is not small....if you want actual measurements I can get them for you...just let me know. It is 50'ft of 5/8" OD copper tubing (1/2" ID). I went with the 5/8" OD so I could use standard fittings. I probably didn't "save" any money building it myself...but I got exactly what I wanted and I enjoyed making it.
Not sure what my total was...over $100 for sure.
I will have to modify it....found out my "whirlpool" arm is not low enough....the end was above the wort line so I had to keep the flow very, very low...didn't want to cause any HSA (hot side aeration).