Nearby help is good. Clipless is more of a personal preference and so is track standing - most FG riders will learn that within a couple months or so. Not a hard skill. Though if the guy lives 3 minutes away and rides clipless, I think that's just stupidity... putting those shoes on and taking them off will be another minute added to his 3 minute commute.

Again, building a bike outright is discouraged by people because you can't know what you want exactly on a bike unless you rode that type of bike for a while.

For example, I didn't know that I wanted right-side pegs only on my BMX and just got two full sets (expensive pegs, too. $80 for the two pairs) and didn't really do anything with the left-side pegs that I took off. Nor did I see that I didn't need gyro brakes ($40) because flatland riding for me didn't involve me using back brakes.

That's $80 that I spent on parts that I gave away as time passed by because I didn't know what I really wanted.

You will make those mistakes on a fixie if you build it up and it's also your first one.
It is possible to build a fixie bike for $700. My estimates don't include labour expenses, though, as my friend has all the tools I need and I know how to build a bike except for the bottom bracket and forks (my buddy helps me with this).

Frame material is important for preferences and preferred performance.
Frame geometry is important for preferences and preferred performance.
(Same deal with forks)

Parts that you can cheap out on IMO (some will say you can't cheap out anywhere, I disagree)
-Handlebars. You can pick up cheap ones off a co-op. Look through their "used" bin.
-Wheelset. Pretty essential so I actually don't recommend this, but a $150 wheel set and $600 wheel set will feel the same to a beginner anyways.
-Pedals. You can again look a co-op's "used" bin. I recommend MKS Sylvan Track pedals though, will run you about $40 but will improve quality of the ride.
-Cogs. You don't need a $60 cog, a $5 one works just as well.
-Chainring. Same deal as cogs, except prices will be more expensive.
-Chain. If it works, it works.
-Cranks. If it works, it works.
-Grips. You can tape it down with road bike tape or get some cheapo grips from a local BMX store.
-Saddle. Though, this is your ass we're talking here, so feel free to go all crazy.
-Tires. Most stock online bikes actually come with pretty decent tires - makes the ride comfy. If you're building from ground up, though, I'd go for Gatorskins. $60 ish.
-Brakes / levers are one thing that's iffy. Some people start only running front brakes after 3 days of riding fixed, and some people go brakeless within a month. So that's $60 you essentially wasted. Get some cheap brakes that work, but you'll most likely be only running front brakes. I don't know anyone that's running both brakes on their FG.

PS: More expensive =/ better performance!
I can buy a 61cm decked out custom made frame but it won't fit me.
A 53cm hi-tensile steel frame would perform better for me. Fits me.

KEEP THOSE THINGS IN MIND.