Permanent Multiplier

Multipliers add together, so if you have 5x and buy 10x from shop your new multiplier will be 15x.
Max Multiplier level is 50.
The table below shows Multiplier Levels & Range and Multiplier from Ruby Shop & Wheel Spins.

Lvl	Multiplier	Range	Both Free/Shop	Free Wheel Spins	Shop Multipliers
1	1	1 - 50	2	3	5	10
2	5	51 - 250	10	15	25	50
3	25	251 - 1,250	50	75	125	250
4	125	1,251 - 6,250	250	375	625	1,250
5	625	6,251 - 31,250	1,250	1,875	3,125	6,250
6	3,125	31,251 - 156,250	6,250	9,375	15,625	31,250
7	15,625	156,251 - 781,250	31,250	46,875	78,125	156,250
8	78,125	781,251 - 3,91e6	156,250	234,375	390,625	781,250
9	390,625	3,91e6 - 19,53e6	781,250	1,17e6	1,95e6	3,91e6
10	1,95e6	19,53e6 - 97,66e6	3,91e6	5,86e6	9,77e6	19,53e6
11	9,77e6	97,66e6 - 488,28e6	19,53e6	29,230e6	48,83e6	97,66e6
12	48,83e6	488,28e6 - 2,44e9	97,66e6	146,48e6	244,14e6	488,28e6
13	244,14e6	2,44e9 - 12,21e9	488,28e6	732,42e6	1,22e9	2,44e9
14	1,22e9	12,21e9 - 61,04e9	2,44e9	3,66e9	6,10e9	12,21e9
15	6,10e9	61,04e9 - 305,18e9	12,21e9	18,31e9	30,52e9	61,04e9
16	30,52e9	305,18e9 - 1,53e12	61,04e9	91,55e9	152,59e9	305,18e9
17	152,59e9	1,53e12 - 7,63e12	305,18e9	457,76e9	762,94e9	1,53e12
18	762,94e9	7,63e12 - 38,15e12	1,53e12	2,29e12	3,81e12	7,63e12
19	3,81e12	38,15e12 - 190,73e12	7,63e12	11,44e12	19,07e12	38,15e12
20	19,07e12	190,73e12 - 953,67e12	38,15e12	57,22e12	95,37e12	190,73e12
21	95,37e12	953,67e12 - 4,77e15	190,73e12	286,10e12	476,84e12	953,67e12
22	476,84e12	4,77e15 - 23,84e15	953,67e12	1,43e15	2,38e15	4,77e15
23	2,38e15	23,84e15 - 119,21e15	4,77e15	7,15e15	11,92e15	23,84e15
24	11,92e15	119,21e15 - 596,05e15	23,84e15	35,76e15	59,60e15	119,21e15
25	59,60e15	596,05e15 - 2,98e18	119,21e15	178,81e15	298,02e15	596,05e15
26	298,02e15	2,98e18 - 14,90e18	596,05e15	894,07e15	1,49e18	2,98e18
27	1,49e18	14,90e18 - 74,50e18	2,98e18	4,47e18	7,45e18	14,90e18
28	7,45e18	74,50e18 - 372,53e18	14,90e18	22,35e18	37,25e18	74,51e18
29	37,25e18	372,53e18 - 1,86e21	74,51e18	111,76e18	186,26e18	372,53e18
30	186,26e18	1,86e21 - 9,31e21	372,53e18	558,79e18	931,32e18	1,86e21
31	931,32e18	9,31e21 - 46,57e21	1,86e21	2,79e21	4,66e21	9,31e21
32	4,66e21	46,57e21 - 232,83e21	9,31e21	13,97e21	23,28e21	46,57e21
33	23,28e21	232,83e21 - 1,16e24	46,57e21	69,85e21	116,42e21	232,83e21
34	116,41e21	1,16e24 - 5,82e24	232,83e21	349,25e21	582,08e21	1,16e24
35	582,08e21	5,82e24 - 29,10e24	1,16e24	1,75e24	2,91e24	5,82e24
36	2,91e24	29,10e24 - 145,52e24	5,82e24	8,73e24	14,55e24	29,10e24
37	14,55e24	145,52e24 - 727,60e24	29,10e24	43,66e24	72,76e24	145,52e24
38	72,76e24	727,60e24 - 3,64e27	145,52e24	218,28e24	363,80e24	727,60e24
39	363,80e24	3,64e27 - 18,19e27	727,60e24	1,09e27	1,82e27	3,64e27
40	1,82e27	18,19e27 - 90,95e27	3,64e27	5,46e27	9,09e27	18,19e27
41	9,09e27	90,95e27 - 454,75e27	18,19e27	27,28e27	45,47e27	90,95e27
42	45,47e27	454,75e27 - 2,27e30	90,95e27	136,42e27	227,37e27	454,75e27
43	227,37e27	2,27e30 - 11,37e30	454,75e27	682,12e27	1,14e30	2,27e30
44	1,14e30	11,37e30 - 56,84e30	2,27e30	3,41e30	5,68e30	11,37e30
45	5,68e30	56,84e30 - 284,22e30	11,37e30	17,05e30	28,42e30	56,84e30
46	28,42e30	284,22e30 - 1,42e33	56,84e30	85,27e30	142,11e30	284,22e30
47	142,11e30	1,42e33 - 7,10e33	284,22e30	426,33e30	710,54e30	1,42e33
48	710,54e30	7,10e33 - 35,53e33	1,42e33	2,13e33	3,55e33	7,11e33
49	3,55e33	35,53e33 - 177,64e33	7,11e33	10,66e33	17,76e33	35,53e33
50	17,76e33	177,64e33 - ∞	35,53e33	53,29e33	88,82e33	177,64e33

Notes

Each level consists of 50 "base multiplier" points.

Each time it levels up, new available multipliers will receive a x5 boost.

This means that, except for level 1, you'll start next level with 50+ (from previous level) / 5 (boost) = 10 base multiplier, so if you purchase another 10x multiplier right after a level-up your multiplier value will be doubled.