There are many inconsistencies that are causing your command to fail. Here was your old data.

1   VillagerData: {
2       profession: butcher,
3       level: 99,
4       type: plains
5   },
6   CustomName: ""Butcher Miles"",
7   NoAI: 1,
8   Invulnerable: 1,
9   Offers: {
10      Recipes: [
11          {
12              buy: {
13                  id: "paper",
14                  tag: {
15                      display: {
16                          Name: [
17                              {
18                                  "text": "Drachma",
19                                  "color": "#ffff66"
20                              }
21                          ],
22                          Enchantments: [
23                              {
24                                  id: fortune,
25                                  lvl: 1
26                              }
27                          ],
28                          Lore: [
29                              {
30                                  "text": "Money, you use it to buy things.",
31                                  "italic": true,
32                                  "color": "white"
33                              }
34                          ]
35                      }
36                  },
37                  Count: 3
38              },
39              maxUses: 5,
40              sell: {
41                  id: "cooked_chicken",
42                  tag: {
43                      display: {
44                          Name: "Miles' Tasty Chicken Wings",
45                          Lore: [
46                              "Yummy!"
47                          ]
48                      }
49                  },
50                  Count: 1
51              },
52              rewardExp: 0b
53          },
54          {
55              buy: {
56                  id: "paper",
57                  tag: {
58                      display: {
59                          Name: [
60                              {
61                                  "text": "Drachma",
62                                  "color": "#ffff66"
63                              }
64                          ],
65                          Lore: [
66                              {
67                                  "text": "Money, you use it to buy things.",
68                                  "italic": true,
69                                  "color": "white"
70                              }
71                          ],
72                          Enchantments: [
73                              {
74                                  id: fortune,
75                                  lvl: 1
76                              }
77                          ]
78                      },
79                      Count: 4
80                  },
81                  maxUses: 3,
82                  sell: {
83                      id: "rabbit_stew",
84                      tag: {
85                          display: {
86                              Name: "Miles' Delicious Rabbit Stew",
87                              Lore: [
88                                  "Works wonders!"
89                              ]
90                          }
91                      },
92                      Count: 1
93                  },
94                  rewardExp: 0b
95              }
96          }
97      ]
98  }
99

Problems

1. Lines 17–20: When you enter JSON, the entire raw JSON text is a string tag, not NBT formatted like JSON. For example, the following is incorrect:
   
   and the following is correct:
   
2. Lines 22–27: Enchantments is in the wrong place. It should be outside display but still inside tag.
3. Lines 28–31: Same problem as #1. Each item within the Lore tag should be a string tag containing raw JSON text, not compounds simulating JSON.
4. Lines 44–47: Here, you forgot that names have become JSON text components. Just like line 6, you can use " or you can use a full JSON component like in the images above.
5. Lines 59–64: Same problem as #1.
6. Lines 65–71: Same problem as #3.
7. Lines 72–77: Same problem as #2.
8. Lines 85–90: Same problem as #4.

Just fix those 8 and you'll be good to go!