For 5 players, I'd recommend one of the following minimum-count tournament sets.
T25-base -- 20k stacks (200bb, 25/50), 12/12/5/6/2:
60 x T25
60 x T100
26 x T500 (includes 1x for color-ups)
67 x T1000 (includes 7x for color-ups)
10 x T5000
-------------------
223 chips
Alternate T25-base (8/8/4/7/2 stacks):
40 x T25
40 x T100
20 x T500
40 x T1000 (includes 5x for color-ups)
10 x T5000
-------------------
150 chips
T100-base -- 40k stacks (200bb, 100/200), 15/5/11/5:
75 x T100
25 x T500
55 x T1000
29 x T5000 (includes 4x for color-ups)
-------------------
184 chips
Alternate T100-base (10/4/7/6 stacks):
50 x T100
20 x T500
35 x T1000
33 x T5000 (includes 3x for color-ups)
-------------------
138 chips
T500-base -- 200k stacks (200bb, 500/1000), 10/10/7/8:
50 x T500
50 x T1000
50 x T5000 (includes 15x for color-ups)
40 x T25000
--------------------
190 chips
T1-base -- 400 stacks (200bb, 1/2), 10/8/10/1:
50 x T1
40 x T5
50 x T25
8 x T100 (includes 3x for color-ups)
----------------
148 chips
With a $300 budget, that puts your per-chip range somewhere between $1.34 and $2.17 per chip, depending on which chip set is chosen.
Custom ceramics, ceramic hybrids, and low-denomination Paulson clay chips are all within that range, plus stock and semi-custom clays from CPC or Key West. A second-hand Gemaco clay set (PCF, Monaco, Elite) should also be in that price range.
Get samples.